Abstract
Time-of-flight inelastic neutron scattering measurements on Sr2IrO4 single crystals were performed to access the spin Hamiltonian in this canonical Jeff=1/2 spin-orbital Mott insulator. The momentum of magnetic scattering at all inelastic energies measured is revealed to be L independent, indicative of idealized two-dimensional in-plane correlations. We model the in-plane energy and momentum dependence of the excitations, that were measured up to ∼80 meV, and define a spin gap of 0.6(1) meV. Collectively, the results indicate that despite the strongly spin-orbit entangled isospins, an isotropic two-dimensional S=1/2 Heisenberg model Hamiltonian accurately describes the magnetic interactions, confirming a robust analogy with unconventional superconducting cuprates.
| Original language | English |
|---|---|
| Article number | 220402 |
| Journal | Physical Review B |
| Volume | 98 |
| Issue number | 22 |
| DOIs | |
| State | Published - Dec 4 2018 |
Funding
This research used resources at the High Flux Isotope Reactor and Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. Sample synthesis and characterization (AFM) was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. We acknowledge W. Tian and A. I. Kolesnikov for assistance during the neutron measurements. ORNL is managed by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The U.S. Government retains, and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. Government purposes.